Improvement in the manufacture of fire-bricks



UNITED STATES PATENT OFFICE.

J. OSTRANDER AND J. S. HEARTT, OF TROY, NEW YORK.

IMPROVEMENT IN THE MANUFACTURE OF FIRE-BRICKS.

Specification forming part of Letters Patent No. 2|,77-l, dated OctoberI2, 1858.

To all whom it may concern:

Be it known that we, JAMES OSTRANDER and JONAS S. HEARTT,each of thecity of Troy, in the county of Rensselaer and State of New York, havejointly discovered or invented a new and useful Improvement inCompositions for Fire -Bricks, Tiles, or Blocks of every Shape; and wedo herebydeclare that the following is a full and exact description ofthe same.

Our improvement in compositions for firebricks consists inaddingpulverized or ground soapstone or steatite in suitable quantitiesto those fire-brick mixtures heretofore commonly employed, which consistessentially either of raw orunburned fire-clay (with or without kao lin)and fire-sand; or of raw fire-clay (with or without kaolin) and burnedfire-clay, (biscuit,) ground; or of raw fire-clay, (with or withoutkaolin,) ground biscuit, and tire-sand,which soapstone, intimatelymixed with the other ingredients, partially melts or cements themtogether in a peculiar manner during the usual burning of the bricks ina close kiln at a white heat, or thereabout, and thereby not only makesthe bricks tough, so that they will not crumble or break to pieces aseasily as they otherwise would, but also gives them such a structurethat melted slag under a strong pressure and blast will not penetrateinto or adhere to them, as it .will bricks having the same composition,with the exception of the soapstone, at the same time thatthesoapstoneleaves the bricks so porous and refractory that they willnot fly or soften when used as linings to the hottest parts of thecupolaand other furnaces.

In the manufacture of fire-bricks the clay holds the ingredientstogether from the beginning of the molding, and the coarsely-groundburned clay or biscuit, or its partial substitutefire-sand or pulverizedquartz-is necessary to give the bricks the indispensable porosity, whilethe various kaolins, being refractory, easily incorporated with andgenerally cheaper than the clay, are often introduced to lessen the costof the bricks. We add the pulverized soapstone, which partially melts orcements the partstogether in a peculiarmanner during the burning, asabove specified, producing a result very different from that attained byusingsalt, soda, potash, borax, alum,pulverized glass, and othervitrifiable materials for cementing the parts together.

WVhen we use the best fire-clay obtained at Woodbridge, New Jersey,kaolin from Staten Island, New York, fire-sand from the north side ofLong Island, New York, and Baltimore stove-linin g soapstone, we preferto use the in gredients in the following, or about the following,proportions for the various qualities of fire-bricks,viz: for the bestkind, eight parts of pulverized soapstone, seventeen parts of rawfire-clay, and fourteen parts of ground biscuit or burned clay; foranother quality, eight parts of pulverized soapstone, sixteen parts ofraw fire-clay, three parts of kaolin, and twelve parts of groundbiscuit; for another kind, eight parts of pulverized soapstone, eighteenparts of raw fire-clay, eleven parts of ground biscuit, and two parts offire-sand; for an other grade,eightparts of pulverized soapstone,sixteen parts of raw fire-clay, three parts of kaolin, ten parts ofground biscuit, and two parts of fire-sand for another variety, eightparts of pulverized soapstoue,t-wen ty-one parts of raw fire-clay, andten parts of fire-sand; and for another, eight parts of soapstone,pulverized,twenty parts of raw fire-clay, four parts of kaolin, andseven parts of fire-sandall by weight.

The quantity of soapstone used may vary from ten to sixty per cent. ofthe whole mixture, with generallya beneficialefi'ect, although weconsider that twenty per cent., or thereabout, of Baltimore soapstoneproduces the best result. If forty to sixty per cent. of soapstone isintroduced, the bricks are aptto soften or run in burning, if located inthe hottest parts of the kiln. As the quality of soapstone variesconsiderably the quantity used must vary accordingly. Thus thirty percent. of Baltimore stove-lining soapstone is generally about equal totwenty per cent. of that from Massachusetts or Vermont.

Fire-clays, fire-sands, and kaolins from different localities alsodiffer more or less in quality, but the experienced fire-brickmanufacturer will generally know by merely inspecting the ingredientsabout how much biscuit, sand, soapstone, and kaolin of aparticularvarietyshould be used to produce acertain quality of bricks.

In manufacturing the bricks with ground soapstone as a constituent part,we fill the pit with thin alternate layers of the ingredients, moistenthem with water, mix the parts intimately together by running the wholethrough a suitable mill, or by other means, mold and drythe bricks, andfinally burn them in a close kiln, all in the manner commonly practicedin manufacturing fire-bricks when no soapstone is' manufacture offire-bricks by using it as aningredient in combination Withvthecommonlyused mixtures of fire-sand or granulated burned fire-clay andraw fire-clay, with or without kaolin, as herein specified.

Having thus described the nature and manner of practicing ourimprovement, What We claim as our joint invention, and desire to secureby Letters Patent, is-

The manufacturing of fire-bricks, tiles, or blocks of a compositionconsisting essentially of pulverized steatite or soapstone, rawfireclay, (with or without kaolin,) and fire-sand or ground biscuit, orboth, the ingredients being mixed in the ratios hereinspecified, or inany other available proportions, as set forth.

JAMES OSTRANDER. JONAS S. HEARTT.

Witnesses: V V

GEO. R. SEYMOUR, GEORGE DAY.

